Messages in this thread | | | From | Nick Desaulniers <> | Date | Thu, 25 Feb 2021 13:01:04 -0800 | Subject | Re: [PATCH] linux/compiler-clang.h: define HAVE_BUILTIN_BSWAP* |
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On Thu, Feb 25, 2021 at 12:06 PM Andrew Morton <akpm@linux-foundation.org> wrote: > > On Thu, 25 Feb 2021 12:03:48 -0800 Kees Cook <keescook@chromium.org> wrote: > > > On Thu, Feb 25, 2021 at 05:45:09PM +0100, Arnd Bergmann wrote: > > > From: Arnd Bergmann <arnd@arndb.de> > > > > > > Separating compiler-clang.h from compiler-gcc.h inadventently dropped the > > > definitions of the three HAVE_BUILTIN_BSWAP macros, which requires falling > > > back to the open-coded version and hoping that the compiler detects it. > > > > > > Since all versions of clang support the __builtin_bswap interfaces, > > > add back the flags and have the headers pick these up automatically. > > > > > > This results in a 4% improvement of compilation speed for arm defconfig. > > > > > > Fixes: 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h mutually exclusive") > > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > > > Cc: stable@vger.kernel.org > > I figured 4% better compile time isn't significant enough to justify a > backport. Thoughts?
If I made a mistake in 815f0ddb346c, then it would be important to correct it since 815f0ddb346c has existed for a few stable branches (first landed in v4.19-rc1). Acked-by: Nick Desaulniers <ndesaulniers@google.com>
> > > Reviewed-by: Kees Cook <keescook@chromium.org> >
-- Thanks, ~Nick Desaulniers
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